Pulverized-fuel-feeding system



w. 0. SAMSLER.

PULVERIZED FUEL FEEDING SYSTEM. APPLICATION FILED APR. 19. I918.

1A1 2 642., Patented p 11, 1922.

2 SHEETS-SHEET I.

FEEL.

4- a? w L I 5 5 6 I W & la 1 232 29 M A 7 2 8 L I S w WITNESSES w. 0.AMSLER. PULVERIZED FUEL FEEDING SYSTEM.

APPLICATION FILED APR. 19; 1918.

1,4111 2,6420 Patented p 11, 1922.

2 SHEETSSHEET 2.

WITNESSES I ferred to application,

. United States t rtar caries.

WALTER O. AMSLER, 0F

EDGEWOOD, PENNSYLVANIA.

PULVERIZED-FUEL-FEEDING SYSTEM.

Application filed April 19,

To all whom it may concern? Be it known that I, WALTER O. AMsLER,acitizen of the .United States, residing at 'Edgewood, in the county ofAllegheny and State of Pennsylvania, have invented certain new -anduseful Improvements in Pulverized-Fuel-Feeding Systems, of which thefollowing is a specification.

My invention relates to new and improved means for feeding pulverizedfuel to a furnace or other fuel consuming device, or to a plurality offuel consuming devices, and the present invention more particularlyrelates to means of the character set forth in Letters Patent granted tome March. 8, 1921,N 1,370,872. In the invention disclosed in the abovereas well as in the present invention, ll employ means designed tosupply a constant and uniform fuel supply to a single or to a pluralityof fuel consuming devices; means for maintaining a uniform fuel densityat each furnace or consuming device; and means for maintaining, at apoint in the system, an excess of powdered fuel in suspension sufficientto saturate an air stream or fluid carrier passed through the fuel whilein suspension.

The present invention includes certain. modified forms of means foraccomplishing the ends abovespecified, and, further, includes means forpreventing clogging of the system and means for treating the air orfluid carrier before it is introduced to the system.

In the accompanying drawings, which illustrate applications of myinvention,

Fig. 1 1s a diagrammatic elevational view of a powdered fuel systemembodying my invention and showing in section a portlon of a fuelconsuming device;

Fig. 2 is a View similar to Fig. 1 showing the air admission meansarranged at a different point in the system; A

Fig. 3, an enlarged detail view partly in section and partly inelevation particularly showing the means for introducing the fuel to theclosed circuit;

Fig. 4, a vertical sectional view taken on line fr-4C of Fig. 3; and

Fig. 5. a view similar tine 5--5 of Fig. 3.

Referring to the drawings, 1 designates a bin designed to contain thepowdered fuel to be introduced to the system, said fuel beto Fig. 4taken on Specification of Letters Patent.

Patented Apr. ilil, 1922..

191a. Serial no. 229,633.

ing supplied to the bin through a pipe 2 connected with the pulveriz'ingapparatus,

not shown.

As shown by Figs. 1 and 2, my invention contemplates supplying one ormore fuel consuming devices with fuel carried thereto by a constantlycirculating fluid stream, and while the drawings (Fig. 1) show only asingle fuel consuming device 3, a plurality of furnaces or devicesdesigned to be connected with the main feed pipe 4 by branches 5 may beemployed. The branches 5 are each provided with a valve 5 adapted tocontrol the passage of the fuel therethrough.

The circulation of the fluid stream and the fuel carried thereby iseffected by a fan or blower of any suitable type. In thedrawings, 6indicates the fan. In the form of Fig. 1, the return pipe 7 communicateswith the inlet side of the fan 6 through a fuel feed measuring andmixing structure 8, an

outlet therefrom and a pipe connection 10.

In the construction of Fig. 2, the return pipe 7 leads directly to theinlet side of the fan or into the connection 10 beyond the structure 8.

The construction of Fig. 1 further differs from that of Fig. 2 in thatthe former admits air to the system at a point in the return pipe inadvance of the fuel admitting and mixing structure'8, while the latterform admits the air at a point adjacent to the structure 8 and notdirectly into the return p1pe.

For the purpose of providing for and maintaining a constant circulationof a fluid carrier and the fuel carried thereby in the forms shown byFigs. 1 and 2, 1 form a closed circuit including, as illustrated, pipe4:, return pipe 7, structure 8, fan structure 6, and connections betweenthe structure 8 and fan 6. Air or other fuel carrier to take the placeof that fed to the fuel consuming device or devices -is automaticallyintroduced into the closed circuit at any convenient point beyond thefuel consuming devices and for the purpose of introducing this air orother fluid, I employ an inwardly operable valve 11 designed to beoperated by the partial vacuum created in the closed circuit due to thedischarge therefrom of the fluid and fuel. This valve 11 may be locatedas shown in Fig. 1, or it may be located as in Fig. 2, or at some otherpoint in the system.

Prior to the introduction of the fluid carwithin chamber 17 I rier,particularly where atmospheric air is employed as the carrier, Ipreferably dry the air by passing it through a cooling or refrigeratingdevice 12.

' To successfully operate powdered fuel feeding systems of the class ofthe present invention, and to provide the desired uniform fuel densityat a furnace or at each.

furnace throughout the system, I consider it essential to create andmaintain at a point in the system an amount of powdered fuel insuspension of sufficient quantity to saturate a stream or fluid carrierpassed through the suspended 'fuel. This is to be distinguished from thepractice of passing or dropping a quantity of pulverized fuel into anair or other moving stream.

As the quantity of powdered fuel or fuel dust carried by an air streamis proportional to the square of the speed of the air stream, it will beevident that with a constant speed and an excess of powdered fuelmaintained in suspension, the density of the fuel in the stream as itleaves the point where the fuel is introduced to the system will beconstant. Further, the density of the fuel will remain uniformthroughout the closed circuit regardless of the quantity of fuel takenfrom the stream while in transit, up to some point in the circuit Whereadditional air is introduced to replace the air utilized.

The means for introducing the fuel to the fluid carrier as illustrated,includes a casing 13 having an inlet nozzle 14 designed to be coupledwith the bin 1 by a coupling member 15. Casing 13 has its interiordivided into a rotor chamber 16, chamber 17, and a lowerchamber 18.Mounted within chamber 16 is a rotor 19 having pockets 20 and provideagitating means 21. Both the pocketed rotor and the agitating means aredriven by a shaft 22, which latter is driven by a motor 23 and theintermediate gearing 24 and 25. 26 designates a baflie plate forpreventing the feed of fuel directly from the fuel inlet to the interiorof the casing. Bafiie plate 26 is carried by an end cover member 27adapted to be secured to the casing 13 byany suitable .means. Said coveris also provided with a nozzle 28 adapted, in the form of Fig. 1, to beconnected with the inner end of the return pipe The agitating chamber 17which is preferably of considerable area communicates with an outletnozzle 29 formed on an end cover member 30,, and said nozzle is incommunication with the inlet side of the fan 6 by means of pipe 10.

Chamber 17 having its positively driven agitating means 21, providessimple and eflicient means for maintaining an excess. of fuel insuspension. The fluid ,ca'rrier pass ing through this chamber becomessaturated an excess p pe connection between In order to prevent an-undesirable ac-' cumulation of fuel in the interior of the casing 13, Iprovide means for carrying the surplus fuel from the chamber 18 to thebin 1. These means, as illustrated, include a pivotally mounted plate orshelf 31 having a shaft 32; a counterbalanced arm 33 being secured toand rotatable with the shaft, said arm carrying a weight 34. Weightedarm 33 functions to first maintain shelf 31 in position to catch thesurplus fuel and then, when moved, due to the weight of the fueloverbalancing the weight 34, to actuate a valve mechanism. These meansare designed, after a predetermined load has accumulated on the shelf,to automatically operate a valve structure 35 which latter controls thepassage of air under pressure through pipe 36. The air may be suppliedfrom any suitable source, not shown, and is introduced to chamber 18 asparticularly shown by Fig. 3. This air, or other fluid, meeting thesurplus fuel in chamber 18, carries said fuel through pipe 37 up to andinto the bin 1. 38 designates a turn buckle construction connecting theweighted arm 33 and the valve operating lever.

What I claim is 1. In a system for feeding pulverized fuel to one ormore furnaces, the combination with a furnace branch pipe and a fuelsupply bin, of a closed conveyor circuit in which a continuouslycirculating stream is maintained, said closed circuit provided with ablower, a pipe connection from the ..blower to the branch pipe, 9.return pipeconnection from the branch pipe in communication with theblower, and a fuel supply device having means for maintaining an excessquantity of fuel in suspension; means associated and cooperating withthe fuel supplying device for passing a surplus of fuel from said deviceto the supply bin, and means for admitting fuel free fluid to thatportion of the stream flowing from the branch pipe toward the blower.

2. In a system for feeding pulverized fuel to one or more furnaces, thecombination with a furnace branch pipe and a fuel supply b1n, of aclosed conveyor circuit in which a continuously circulating stream ismaintained, said closed circuit including a blower, a pipe connectionfrom the blower to the branch pipe, a return pipe connection from thebranch pipe to the blower, a fuel supplylng devicehaving meansfor'maintaining quantity of fuel in suspension, a

the supplying device and the return pipe;

means associated emme I Q and cooperating with the fuel supplyingdesuspension therein, and automatically opervice for passing a surplusof fuel from said. able means associated with the fuel supplydevice tothe supply bin, and means for passing device for passinga surplus offuel from ing fuel free fluid to the supplying device the supplyingdevice to the fuel supply bin,

5 and through the fuel suspended therein. In testimony whereof I afi'ixmy signature 15 3. In a system for feeding pulverized fuel, in presenceof two Witnesses. the combination with a fuel supply bin and WALTER O.AMSLER. a closed conveyor circuit including a fuel. 7 Witnesses: supplydevice, said device having means for J. M. GEOGHEGAN,

'1-0 maintaining an excess quantity of fuel in Low WINEMAN.

